Internal combustion engine



sept. 21, 1937.

VH. TRIEBYNIGG..

INTERNAL 4comaus'rion ENGINE original Filed Feb'.` 16, 19.32

2 Sheets-Sheet 2 Compl-aimed afrreerra/r Fl g. 3

l 'nyenfon' /m'fm cylinders is abandoned. The advantage gained.

Patented Sept. 21,. 1937 PATENT OFFICE INTERNAL OOMBUSTION ENGINE Heinrich Triebnigg,l Cologne, Germany, assignor to Humboldt-Deutzmotoren A. G.,

Deutz, Germany Cologne,

Original application February 16, 1932, Serial No.

593,378. Divided and this application September-24, 1934, Serial No. 745,344.

February 1s, 1991 5 claims;

This invention relates to locomotives driven by internal combustion engines, preferably ,Diesel engines, and apparatus forv starting and accelerating such locomotives.

This application is a division ofapplication Serial No. 593,378, filed February 16, 1932, now Patent.No. 2,010,469, dated August 6, 1935.

The invention makes possible the starting of the driving engineof a locomotive from its statel of rest without disengaging the driving connection to the axles and without the use of transmission gears` to `step up the drivingy ratio as the locomotive accelerates. According to the invention, the combustion of fuel and compressed air takes place begnni'ng'with the' very rst revolution, and the usual manner of starting the engine'by introducing `solely compressedair'into the working hereby is that compressed air storage capacity of the engine need be only very small, since the pressure is raised in the engine cylinder by the combustion of fuel. Thus itis even possible to supply the compressed air by a relatively small auxiliarycompressor. The compressed air and fuel Without air are brought into the combustion chamber, each through a separate valve for themajor part of the working stroke of the piston. Ignition is effected by a glowing body, for example an electrically heated element.

In the operation of the engine during starting,

according to the invention, a low combustion pressure is used, as compared with the ordinary Diesel engine operation in which self-ignition or compression-ignition in consequence of the high degree ofcompression, takes place. The low combustion pressure may be secured for example by blowing out orl releasing part of the air drawn in by the piston during the suction stroke, or by throttling the intake manifold. The pressure in this operation may even be reduced to atmospheric pressure in the case that a small tractive force is required. On the other hand, the com" pressed air and fuel are charged into the cylinder beginning about the inner dead` center over a comparatively large part ofthe working stroke, for example 50%. By these two measures, i. e., lowering the combustion pressure and extending the time of charging the combustion chamber during the working strok-e, an indicater diagram is obtained which is similar to that of a steam engine. By reason of this indicator diagram, the engine may act on the axles of a locomotive simply by means of connecting rods and cranks as is usual in steam locomotives, no other gears being required. l

In Germany (ci. 12s- 26) Fig. 1 shows curves of the regulation of a Diesel.A

engine according to the' instant invention for different speeds attained by the locomotive,

Fig. 2 represents the indicator diagrams of the engine at corresponding speeds of the locomotive indicated on the axis of abscissas in Fig. 1, and

Fig. 3 is an elevational view, partly in section, of the engine with the regulating means therefor.

The means for executing the above described mode of operation, such as the fuel valves for airless injection, the compressed air` valve and scavenging air inlet and exhaust ports or valves, respectively, are of the usual kind. The actuating means for the valves are designed accordingly. An ignition device, as for example, an electrically heated wire spiral of a heat resisting material, as nichrotherm or a ceramic substance as carborundum or silicon, is always necessary for the starting operation. The heating element must possess a high caloric capacity which renders it indifferent to the cooling effect of fuel or compressed air thrown against it. Finally the valve for diminishing the compression in the engine is new,as cornpared with the usual type.

The mode -of operation and means according to this invention in the transition from starting the engine with combustion of fuel and compressed airvto the normal Diesel-cycle with compressionignition will now be described. During acceleration of the engine a gradual Atransition takes place to the normal working cycle, for example the socalled Diesel-cycle, in whichself-ignition of the fuel occurs due to the high compression temperature. vAs the engine is accelerated, the charge of compressed air'is gradually decreased to zero by reduction of the charging time relative to the working stroke. Simultaneouslythe time of fuel injection is reduced, which time is generally proportional to the charge of -fuel and which is much longer during starting than in normal working of the engine. The normal compression pressure is also restored during the Sametime. In accord- .finely without impinging on the cylinder Walls.

This valve is loaded, for example, to about 50 to 150 atmospheres. The nozzle holes accordingly are dimensioned small, or another kind of resistance is provided in the valve. 'Ihe foggy spray of fuel will ignite surely upon touching the glowing ignition body. The pump pressure for this nozzle is comparatively low, as on account of the proximity of the valve to the ignition body, the fuel particles need not traverse the whole combustion chamber. It Would indeed be disadvantageous if the fuel would reach the relatively cool cylinder wall without igniting. The second fuel valve must be dimensioned for the purpose of injection in the normal Diesel-cycle. This valve is loaded, for example 4to about 300 atmospheres by a spring, against the compression force of which the valve opens. The operating mechanism of the compressed air valye and of the fuel pumps are regulated together; so that when first starting, only compressed air and the first fuel pump operate and give their maximum charge. With growing speed, and in dependency thereon, both air and the first fuel pump are cut off gradually, and simultaneously the second pump begins to act through the other fuel valve. For a certain time during acceleration, the delivery of both pumps may overlap.

A more detailed manner of regulation is diagrammatically illustrated in Fig. 1. The abscissas represent the travelling speed of the locomotive in kilometers per hour. The vertical distances (ordinates) from the base line to the curve a are the degrees of angle of'the crank circle in the working stroke counted from the inner dead center, during which compressed air is admitted to the cylinder. At 50 lm. per hour the air is cut off altogether. The curve b, representing the angular duration of fuel injection through the first (starting) fuel valve, is very similar. At 40 kms. per hour, the fuel delivery of this valve is nearly interrupted. For highery velocities always a very small amount is discharged to avoid choking of the nozzles. The injection pressure c of starting compressed air rises from nearly 15 atmospheres at the beginning of operation to about 40 atmospheres at 50 kms. per hour for the reason that the increasing combustion pressure in the cylinder must be overcome. The second fuel pump begins to operate, for example at 20 kms. per hour, as shown by .the curve d,' and at almost 40 kms. per hour, where the actual Dieselcycle begins, fuel is injected by the second fuel pump continuously while the crank is traveling about 50 from top dead center. As the speed increases above 40 kms. per hour the period of delivery drops continuously in accordance with the decrease of the tractive force as required by the demand of a constant output of the engine.

In Fig. 2 are shown several indicator diagrams taken during starting and acceleration of a ported-valve two stroke cycle engine, each diagram being placed substantially above the abscissa of Fig. 1 corresponding to the speed at which it is taken. 'I'he diagram shown at the furthest left shows the change of pressure in starting. Compressed air .and-fuel are forced into the cylinder during about 60% of the work stroke. Compression does not take place at this proportion to the height of the lift.

stage and the combustion pressure is relatively low. The second diagram corresponds to a speed of 10 kilometers per hour. Here there is only a slight compression, on account of the pressure and heat losses due to the low piston speed, or on account of the holding open of the compression relief valve for a certain portion of the compression stroke. The combustion pressure is somewhat higher than in the flrst diagram and hour, can be recognized by the pressure peak in the first part of the work stroke. The fourth diagram, which corresponds to a traveling speed of about 40-50 kilometers per hour, is an ordinary Diesel diagram, which shows still a little supercharging by compressed air, and the fifth diaf gram, which corresponds to the traveling speed of kilometers, is a normal Diesel diagram without super-charging.

The regulating mechanism and part of the engine adapted to carry out the cycle described are illustrated in Fig. 3 of the drawings, in which 2 is the working cylinder, and 3 is the piston in its upper dead center position. '.Ihe cylinder 2 has an inlet port 200 and an exhaust port 20|, both controlled by the piston 3. Through the cylinder head 4 there extends an electrically heated ignition element 5, the fuel valve 6 for starting, the fuel valve 1 for the ordinary Dieselcycle, the compressedair starting Valve 8 and the compression relief valve 9. The needle I0 of valve 6 is pressed on its seat II by spring I2, and it terminates in a spiral-grooved point I3 which causes large dispersion of the fuel. The valve opens in the known manner by fuel pressure transmitted by the fuel pump I4 through the pipe line I5. The valve 1 is fed by the fuel pump I6 through the pipe I1. The spring I8 on the needle I0 of valve 1 is stronger than spring I 2 of valve 6. Both fuel pumps and also the compressed air valve 8 are operated by sloped cams I9, 20, 2I slidably mounted on the common shaft 18 which is driven by gears 22 and 23 from the main crank shaft not shown. The shaft 18 is supported in bearings 24 and 25. There are three bell crank levers 26, 21 and 28 fulcrumed at 29, 30 and 3| in the vbracket 32. The stroke of the plunger 33 of the fuel pump is varied with the lift of the cam I9. 'I'he cam is formed so that the plunger always starts to pump through the pressure valve 31 while the piston 3 of the engine is about its inner dead center, and finishes its delivering stroke at a later period in direct The spring 34 effects the suction from the suction channel 35 through the valve 36. The pump I 6 acts on the same principle. The plunger 39 is actuated by the cam 20 in the delivering stroke and by the spring 38 in the suction stroke. The suction channel is designated 4U, the suction valve 44, and the pressure valve 42. The cam 20 is formed so as to pump only aboutthe inner dead center of the engine piston. By shifting the cam, mainly the amount of fuel is varied, but only slightly is the time of injection changed. -The cam 2| opens the compressed air valve 8 against the compression force of the spring 43 by means of the push rod 44 and the bell crank lever 45. This cam is of similar cross section to the cam I9, i. e. by engagingrwith the push rod 44, it opens .the valve always about the inner dead center and `changes the time or duration of communication of the combustion chamber with the source of compressed air. The compressed air is admitted to the valve 8 from the vessel 46 through pipe 41, rotary valve 48 and pipe 49. This valve 48 serves to throttle the air pressure for the initial operation and to render free the full pressure during acceleration of the engine in the manner as shown in the diagram of Fig. 1 by the curve c. The rotaryvalve is adjusted by the hand lever52; The compression relieving valve 9 is held open by the spring 50. 'I'he combustion space then communicates with the atmosphere by way ofthe hole 5I. If the piston 3 moves upward slowly during the compression stroke, as in the very`iirst movement during starting', the current of the outgoing'air will not close the valve`9. But as the engine gains speed the force of the air blown out through the valve 9 will close the valve against the tension of spring 50, and as the pistonA always starts its upward movement 4from the lower dead center with the velocity equal to zero, the closing of the valve occurs earlier in the piston' stroke as the speed of the engine is higher. Thus the full compression is automatically reinstated in dependency of the engine speed. Of course instead of the automatic valve, another cam on the shaft could actuatethe relief valve.

' In the lower part of Figure 3, are shown two gear wheels 53 and 54 meshing together. They are fulcrumed at 55 and 56. Fixed to the wheel 54 is the hand lever 51 and the pin 56. The latter is4 connected to the pin 66 of the bell crank 40 lever 28 bythe rod 6I. The wheel 53 carries a` two-armed lever 59, 61 fixed thereon. The pin 62 of the upper arm 61 is connected to the pin 63 of bell cranklever 21 by rod 64, andthe pin 65 of the 'lower' arm 59 is connected to the pin 68 of the bell crank lever `26 by rod 66.

There are indicated in dot-and-dash lines three positions of the levers 51, 59 `and 61, the correspending positions each marked by the same nu- .merals 0, and 100. 'Ihese numerals signifyv 50 approximately the travelling speeds of the locomotive. If the lever 51, beginning at zero while starting is lowered slowly in harmony with the actual speed, and the speed as indicated on the dial 69, both fuel pumps I4, I6 and the com-- pressed air valve 8 are actuated in a similar manner as required by the diagrams of Fig. 1. The regulating mehanism is shown in the position for 50 km. per hour travelling speed. The push rod 44 is just out of engagement with the cam 2|.

'j 50 The fuel pump I4 delivers very little 4to prohibit choking of the valve 6, and the caml 26 actuates the pump I6 for lnearly the highest amount of delivery. lowering the lever 51 will only shorten the duration of the delivery of fuel by the pump 65 I6 on account of the increased speed 'of operation of cam 26 at higher speeds. Naturally the regulating mechanism may also `be 'set to any other position than to a, conformity of the actual speed and that marked on the dial 69. which 75 only indicates a favorable regulation for starting and accelerating under normal conditions.

second pump per engine stroke.

E. g.'while` driving up a slope after having gained full speed before, the lever 59 will be set back to compressed air fuel combustion to enhance the tractive force of the engine.

Having described my invention, what I claim is: v

1. In an oil injection engine, a cylinder, a piston reciprocating in said cylinder and cooperating therewith to form a combustion chamber, an ignition device in said chamber, a starting fuel valve in said chamber, a second fuel valve for injecting fuel into said chamber, a fuel pump for delivering fuel to said first valve, a fuel pump Afor delivering fuel tosaid second valve, a valve for compressed air, actuating mechanisms for said fuel pumps and said compressed air,valve, regulating means for said actuating mechanisms, said last-mentioned 'means being adapted to control the duration of fuel supply to said rst fuel valve, the duration of opening of said compressed air valve, and the quantityof fuel delivered to said second fuel valve.

2. In an oil injection engine, a cylinder, a piston reciprocating in said cylinder and cooperating therewith to form a combustion chamber, an

y ignition device in said chamber, a starting fuel valve emitting a spray of low force and great dispersion in said chamber, a second fuel valve emitting a spray of higher force and lesser dispersion for. injecting fuelinto said chamber, a fuel pump for delivering fuel to said first valve, a fuel pump for delivering fuel to said second valve, a lvalve for compressed air, actuating mech- 'anisms for said fuel pumps and said compressed air valve, regulating means `for said 4actuating4 mechanisms, said last-mentioned means being' adapted to control the duration of the fuel supply to said first valve in accordance with the duration of opening of said compressed air valve vand to gradually' render operative said seco'nd fuel pump upon the gradual iessening of the duration of opening of said compressed air valve and the decrease in effect of said first fuel valve.

3. In an oil injection engine, `a cylinder, apiston reciprocating in said cylinder and.l cooperat-r ing therewith to form a combustion chamber, an

injecting fuel into said chamber, a fuel pump for delivering fuel to said first valve, a fuel pump v 4. An engine as described in claim 1, wherein said first mentioned fuel valve is adjustedl for comparatively low injection pressure and said second fuell valve is adjusted for a higher injec-l tion pressure.

5. An engine as described in claim 3, wherein said regulating means is adapted to stopv the feed of fuel from said second fuel pump at one limit tion.

. HEINRIQH TRIEBNIGG.

45 ignition device in said chamber, a startingfuel f valve in said chamber', a second fuel valve for position and to adjust said first fel pump-to .feed

-a minimumcharge of fuel at its other limit posi- 

